“通常”是什么意思有时，但不总是？因为，您发布的代码看起来很好，并且不会在我的测试用例中引发错误。
示例对象：

SQL> CREATE TABLE cpm_t
  2  (
  3     id       NUMBER,
  4     org_id   VARCHAR2 (20),
  5     title    VARCHAR2 (20)
  6  );

Table created.

SQL> CREATE TABLE cpm_hist_t
  2  (
  3     hist_id   NUMBER
  4  );

Table created.

SQL> CREATE OR REPLACE TRIGGER cpm_hist_id_trig
  2     BEFORE INSERT
  3     ON cpm_hist_t
  4     FOR EACH ROW
  5  BEGIN
  6     NULL;
  7  END;
  8  /

Trigger created.

SQL> CREATE SEQUENCE cpm_id_seq;

Sequence created.

您的代码（转换为过程;我什么都没改）：

SQL> CREATE OR REPLACE PROCEDURE p_test
  2  AS
  3     cpm_id            PLS_INTEGER;
  4     cpm_id_to_delete  PLS_INTEGER;
  5  BEGIN
  6     BEGIN
  7        SELECT id
  8          INTO cpm_id_to_delete
  9          FROM cpm_t
 10         WHERE title LIKE '%My Contract%';
 11
 12        DELETE cpm_hist_t
 13         WHERE hist_id = cpm_id_to_delete;
 14
 15        -- Deactivate the trigger
 16        EXECUTE IMMEDIATE 'ALTER TRIGGER CPM_HIST_ID_TRIG DISABLE';
 17
 18        DELETE cpm_t
 19         WHERE id = cpm_id_to_delete;
 20
 21        -- Activate the trigger
 22        EXECUTE IMMEDIATE 'ALTER TRIGGER CPM_HIST_ID_TRIG ENABLE';
 23     EXCEPTION
 24        WHEN NO_DATA_FOUND
 25        THEN
 26           NULL;
 27     END;
 28
 29     cpm_id := cpm_id_seq.NEXTVAL;
 30
 31     INSERT INTO cpm_t (id, org_id, title)
 32          VALUES (cpm_id, '7257', 'My Contract');
 33  END;
 34  /

Procedure created.

测试：

SQL> EXEC p_test;

PL/SQL procedure successfully completed.

SQL> SELECT * FROM cpm_t;

        ID ORG_ID               TITLE
---------- -------------------- --------------------
         1 7257                 My Contract

SQL> SELECT * FROM cpm_t;

        ID ORG_ID               TITLE
---------- -------------------- --------------------
         2 7257                 My Contract

SQL>

所以，没什么问题。
您能否发布自己的SQL*Plus会话来说明问题？

您的代码似乎可以正常工作（如果您使用SQL*Plus、SQL Developer等）。然后你需要在PL/SQL块的末尾的新行上添加一个PL/SQL终止符/）。
你可以（取决于你的触发器做什么）重写它：

DECLARE
  CPM_ID_TO_DELETE CPM_T.ID%TYPE;
BEGIN
  BEGIN
    -- Deactivate the trigger
    EXECUTE IMMEDIATE 'ALTER TRIGGER CPM_HIST_ID_TRIG DISABLE';

    DELETE CPM_T
    WHERE TITLE LIKE '%My Contract%'
    RETURNING ID INTO CPM_ID_TO_DELETE;

    DELETE CPM_HIST_T WHERE HIST_ID  = CPM_ID_TO_DELETE;

    -- Activate the trigger
    EXECUTE IMMEDIATE 'ALTER TRIGGER CPM_HIST_ID_TRIG ENABLE';
  EXCEPTION
    WHEN NO_DATA_FOUND THEN
      NULL;
  END;
  Insert into CPM_T (ID,ORG_ID,TITLE) values (CPM_ID_SEQ.nextval,'7257','My Contract');
END;
/

fiddle